1. Field of the Invention
This invention relates to color-forming parasulfonamidodiphenylamines and corresponding sulfonimide dyes that are useful in imaging materials, such as photographic silver salt materials, and processes.
2. State of the Art
Photographic materials for producing silver and dye images are well known. The dye image in such materials generally is produced by a coupling reaction in which a developing agent is oxidized upon development of photographic silver halide followed by reaction of the resulting oxidized form of the developing agent with a coupling agent to produce a dye image. This is described in, for example, Research Disclosure, December 1978, Item No. 17643, published by Industrial Opportunities, Limited, Homewell, Havant, Hampshire, United Kingdom, and U.S. Pat. No. 3,938,995. It has been desirable to provide alternative means for producing a dye image, especially a dye image that enhances a silver image, other than by a coupling reaction. The art does not disclose that the answer to this problem is found in color-forming para-sulfonamidodiphenylamines and corresponding sulfonimide dyes that do not significantly adversely affect the sensitometric properties of the photographic materials.
Compounds that contain a 2,4-dinitroanilino moiety and are arenesulfonamides are described in U.S. Pat. No. 3,284,499 as pesticides. Also, diphenylamines substituted by haloalkylsulfonamido groups are described as antimicrobial agents, anti-inflammatory agents, analgesics and herbicides. These sulfonamides are not compounds of the present invention. Also, no suggestion is found in the art that these sulfonamides have the properties needed for color formation, such as in photographic silver materials.
The term "photographic material" as used herein means a photographic element and photographic composition. For instance, photographic material herein includes a photographic element and composition comprising a sulfonamidodiphenylamine color-forming agent or a corresponding sulfonimide dye according to the invention.
A continuing need has existing for color-forming sulfonamidodiphenylamines and their corresponding sulfonimide dyes that are useful in imaging materials, especially in photographic silver halide materials.